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Your search keyword '"Intermembrane space proteins"' showing total 2 results
Start Over Descriptor "Intermembrane space proteins" Topic mitochondrial proteins
2 results on '"Intermembrane space proteins"'

1. Regulation of COX Assembly and Function by Twin CX 9 C Proteins—Implications for Human Disease.

Author

Gladyck, Stephanie, Aras, Siddhesh, Hüttemann, Maik, and Grossman, Lawrence I.

Subjects
*CYTOCHROME c, *MITOCHONDRIAL proteins, *MITOCHONDRIAL membranes, *ADENOSINE triphosphatase, *CYTOCHROME oxidase, *ELECTRON transport, *OXYGEN in water, *PROTEIN-protein interactions
Abstract

Oxidative phosphorylation is a tightly regulated process in mammals that takes place in and across the inner mitochondrial membrane and consists of the electron transport chain and ATP synthase. Complex IV, or cytochrome c oxidase (COX), is the terminal enzyme of the electron transport chain, responsible for accepting electrons from cytochrome c, pumping protons to contribute to the gradient utilized by ATP synthase to produce ATP, and reducing oxygen to water. As such, COX is tightly regulated through numerous mechanisms including protein–protein interactions. The twin CX9C family of proteins has recently been shown to be involved in COX regulation by assisting with complex assembly, biogenesis, and activity. The twin CX9C motif allows for the import of these proteins into the intermembrane space of the mitochondria using the redox import machinery of Mia40/CHCHD4. Studies have shown that knockdown of the proteins discussed in this review results in decreased or completely deficient aerobic respiration in experimental models ranging from yeast to human cells, as the proteins are conserved across species. This article highlights and discusses the importance of COX regulation by twin CX9C proteins in the mitochondria via COX assembly and control of its activity through protein–protein interactions, which is further modulated by cell signaling pathways. Interestingly, select members of the CX9C protein family, including MNRR1 and CHCHD10, show a novel feature in that they not only localize to the mitochondria but also to the nucleus, where they mediate oxygen- and stress-induced transcriptional regulation, opening a new view of mitochondrial-nuclear crosstalk and its involvement in human disease. [ABSTRACT FROM AUTHOR]

Published
2021
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2. Structural insight into the TRIAP1/PRELI-like domain family of mitochondrial phospholipid transfer complexes

Author

Stephen Matthews, James A. Garnett, Ernesto Yagüe, Thomas Langer, Heather Baldie, Peter Simpson, Xeni Miliara, Inmaculada Pérez-Dorado, Ferdos Abid Ali, Takashi Tatsuta, Medical Research Council (MRC), and Wellcome Trust

Subjects
CARDIOLIPIN, Biochemistry & Molecular Biology, Molecular Sequence Data, Mitochondrion, Biology, 0601 Biochemistry and Cell Biology, Crystallography, X-Ray, Endoplasmic Reticulum, Biochemistry, Protein Structure, Secondary, Mitochondrial Proteins, INTRAMITOCHONDRIAL TRANSPORT, chemistry.chemical_compound, Protein structure, Genetics, Cardiolipin, Humans, Amino Acid Sequence, Inner mitochondrial membrane, Molecular Biology, Phospholipids, Adaptor Proteins, Signal Transducing, PHOSPHATIDIC-ACID, Science & Technology, Binding Sites, IMPORT, Endoplasmic reticulum, Scientific Reports, Intracellular Signaling Peptides and Proteins, Membrane Proteins, Biological Transport, Cell Biology, Mitochondrial carrier, UPS1P, Cell biology, Mitochondria, Protein Structure, Tertiary, INTERMEMBRANE SPACE PROTEINS, chemistry, Membrane protein, Mitochondrial Membranes, Life Sciences & Biomedicine, Hydrophobic and Hydrophilic Interactions, Sequence Alignment, Function (biology), Developmental Biology, Molecular Chaperones
Abstract

The composition of the mitochondrial membrane is important for its architecture and proper function. Mitochondria depend on a tightly regulated supply of phospholipid via intra-mitochondrial synthesis and by direct import from the endoplasmic reticulum. The Ups1/PRELI-like family together with its mitochondrial chaperones (TRIAP1/Mdm35) represent a unique heterodimeric lipid transfer system that is evolutionary conserved from yeast to man. Work presented here provides new atomic resolution insight into the function of a human member of this system. Crystal structures of free TRIAP1 and the TRIAP1-SLMO1 complex reveal how the PRELI domain is chaperoned during import into the intermembrane mitochondrial space. The structural resemblance of PRELI-like domain of SLMO1 with that of mammalian phoshatidylinositol transfer proteins (PITPs) suggest that they share similar lipid transfer mechanisms, in which access to a buried phospholipid-binding cavity is regulated by conformationally adaptable loops. Synopsis The structures of TRIAP1 and its complex with SLMO1 reveal how the PRELI domain is chaperoned during mitochondrial import. Access to an internal phospholipid binding cavity is likely regulated by conformationally adaptable loops. Structures of TRIAP1 and the TRIAP1-SLMO1 complex were solved by X-ray crystallography. The PRELI-like domain of SLMO1 resembles that of mammalian phoshatidylinositol transfer proteins (PITPs). Mutagenesis experiments highlight the roles of an internal hydrophilic cavity and lipid exchange loops in phospholipid extraction. The structures of TRIAP1 and its complex with SLMO1 reveal how the PRELI domain is chaperoned during mitochondrial import. Access to an internal phospholipid binding cavity is likely regulated by conformationally adaptable loops.

Published
2015
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